Carburetor



CARBURETOR Filed April 23,

R. HAMILTON ET AL March 10, 1931.

El Robe/"Z Hamil/0 Herman 1 6/"00/1 E Patented Mar. 10, 1931 UNITEDSTATES PATENT OFFICE ROBERT HAMILTON AND HERMAN V. CROON, OF CHICAGO,ILLINOIS CARBURETOR Application filed April 23, 1927. Serial No.185,999.

Our invention relates to carburetors of the to control the resistance inthe Venturi noztype employed on motor vehicles and more zle; andparticularly to mechanism controlled by the FE gure 4 is a verticalsectional view through choke valve for heating the fuel sprayed intomodified form of nozzle built in accordance 5 the main air passage. withthe features of our invention. 55

In order to augment the vaporization of the As shown on the drawingsfuel sprayed into the main air passage of the The carburetor shown inFigure 1 is subcarburetor, we find it desirable, especially stantiallylike the conventional type of carin cold weather when the vehicle isbeing buretor, with the exception that the Venturi started, to preheatthis passage. In order nozzle shown therein is provided with pretoaccomplish this desirable end we have (ieheating means to be describedmore in detail vised a switch construction controlled by hereinafter.The carburetor comprises a the choke valve of the carburetor andadaptbody 10 including an inlet air passage 11 and ed to automaticallyclose an electric circuit a float chamber 12. Connected to the float 15arranged to preheat the main air passage, chamber 12 is a fuel supply orgasoline line 65 when the choke valve is in its closed position. 13 winch is suitably connected to the tank This construction is such that whenthe choke (not shown) of the vehicle. The fuel line 13 valve is open,the switch is open and when has a lateral tubular extension 14 threadedthe choke valve is closed, the switch is autointo the body defining thefloat chamber 12. matically closed. A needle valve 16 extends into thetubular Our novel preheating mechanism is espemember i l and is adaptedto control the sup cially useful in the starting of the motor and ply offuel delivered to the float chamber in by its use we find that theengine may be set a well known manner. The upper end of into normaloperation in much less time than valve member 16 is carried by a pair ofpivheretofore. otally mounted lever members 17 which In accordance withthe features of the premembers have enlarged ends 18 resting on ferredform of our invention, we provide the op of the float- 19. The rod 16extends upmain air passage of the carburetor with a wardly through anopening 20 in float 19. It Venturi nozzle equipped with an electricalwill be evldent from this illustration that the resistance forpreheating the passage. The rise and fall of float 19 controls th a t 30resistance comprises part of an electrical of fuel discharged into thechamber 12 from circuit controlled by a switch disposed on the theSource of supply. 4 exterior of the carburetor; the switch beingPosltlpned Wlthln the y 10 is 11 right connected directly to the pivotof the choke angle P 1 tube member the "el'tlcal Valve leg 23 of whichextends upwardly toward 85 1 A c Other ob ects and advantages of our in-2 3 2322 5 3; g g figggi g gqffg uleitilbe vention will more fullyappear from the foli U t1 f i lowin detailed description taken inconnec- Ema openmb O (mg 1 W 110 mm mm g the rwcomym drawindwhich thefloat chamber 1s delivered to the tube. D b This opening 25 iscontrolled by a convenillustrates several embodiments thereof and m27inch: the body 10 in a well known manner.

l igure 1 1s vertical sectional view taken The major part of the tube 22is disposed g 5/ Carburetor @nbodylng the matures in the junctionbetween the inlet air passage of P P lnvelltloni 11 and the main airpassage 28 in which is t-l 2 1S a Sectional VleW taken 011 S disposedthe Venturi nozzle 15. This juncstalliiially the line ITHII of Figure l,lOOlilIlg tion is designated by the reference character downwardly; 30.Also it will be noted from Figure 1 that Figure 3 is an enlarged detailsectional the upper end of the leg 23 of tube 22 extends 50 View of ournovel switch construction used a slight ways into the Venturi nozzle 15.

tional needle valve member 26 threaded into The inlet air passage 11 iscontrolled by a choke valve 31 formed inte ral with a pivot member 32journalled at its ends in diametrically opposed boses 33 formed integralwith the body 10. One end of pivot member 32 is connected to a lever 34used to operate the choke valve. The other end of the member 32 isconnected. to a switch construction which will be described more indetail as the present description progresses.

The Venturi nozzle is preferably made of a material such as a metalhaving the inherent quality of offering a relatively high resistance tothe flow of an electrical current. Also the Venturi nozzle 15 comprisesconductor which is insulated from the por tion of the body 1O definingthe passageway 23 by a sleeve of insulation 36. The upper end of nozzle15 is grounded thru the body 10 by means of a small screw 37 threadedthrough the wall of tube 28, the sleeve 36 and into nozzle 15.

The upper end of passageway 28 is provided with an annular flange 38 bymeans of which the carburetor may be secured to the intake manifold (notshown) of the engine. Furthermore, disposed in the upper end of thepassa eway 28 is a throttle valve 39 having formed integral therewith apivotally mounted rod 40 which may be operated in any usual manner.

The lower end of nozzle 15 is held in place by means of a stud or screw41 extending through the wall of passage 28, the sleeve 36 and threadedinto nozzle 15. This stud 41 is insulated from the body 10 by means of asmall bushing 42. The two studs 37 and 41 cooperate to connect anelectrical circuit to the conductor or nozzle 15 and also function toanchor the nozzle to the body 10. \Ve shall now proceed to describe indetail the switch construction 35.

Suitably fastened to one end of the choke valve pivot member 32 is anupwardly extending arm 45 made of any suitable insulation. The upper endof this arm 45 fits in a socket 46 formed integral with one end of anangular switch member 47. The upper end of arm 45 is secured in thesocket 46 by means of a small bolt 48. Also it will be noted that thebolt 48 is used to fasten one end of the electrical conductor 59 to themember 47. The other end of this conductor 49 may be con nected directlyto the battery (not shown) of the vehicle.

The le 51 of member 47 is provided with a cylindrical bore 52 in whichis disposed a compression spring 53. Also disposed in the bore 52 is aplunger 54. having a. slot 55. A pin 56 extends through slot 55 and isanchored at its ends in the leg 51 of member 47. The function of pin 56is to limit the movement of the plunger 54 under the urging effect ofthe spring 53. The external end of the plunger 54 is provided with anenlarged head 58 adapted to abut the head of stud 41 as shown in Figure3. Obviously when the head 58 is in contact with the head of stud 41',the electrical conductor 49 will be connected to the nozzle 15 and thecurrent delivered to the nozzle 15 will travel circumferentially aboutit to the 'stud 37 which is grounded.

The operation of our mechanism is believed to be evident from the abovedetail description. lVhen the cold engine is being initially started, itis customary to close off the supply of air to the carburetor byshutting the choke valve 31. By the closing of valve 31 the member 47 ismoved toward the passageway 28 to bring the plunger 54 into electricalcontact with the stud 41. The head of stud 41 and the head 58 of plunger54 in reality constitute a pair of electrical contacts. Due to theresilient mounting provided for plunger 54, it will be resiliently urgedinto contact with the head of stud 41, thus insuring a good electricalconnection.

Now when this electrical connection is established, the nozzle 15 willfunction as a conductor in the circuit of the vehicle. Moreover, sincethe nozzle 15 is made of a material having a relatively high resistanceto the flow of an electrical current therethrough, it Will become heatedby the current flowing from stud 41 to stud 37, Which latter stud isgrounded. The heated nozzle 15 will inturn preheat the fuel sprayed intothe nozzle from the vertical leg 23 of tube 22. This preheating of thefuel will augment the vaporizing of the fuel and will facilitate thestarting of the engine. 7

As soon as the engine is warmed up, the choke valve 31 is moved to itsopen position and the conductor 49 is automatically disconnected fromthe nozzle 15.

In Figure 4 we have illustrated a modified form of Venturi nozzle 15comprising a cylinder of refractory material 16 having embedded in itsinner surface a spiral resistance wire 61 connected to studs 41 and 37;the stud 41 being connectable to the switch mechanism of our inventionand the stud 37 being adapted to be grounded. The wire 61 is made of amaterial having a high resistance. The operation of this type of nozzleis substantially like the nozzle 15 and it is therefore thought that nofurther description of it is needed.

3 It will be apparent that our novel Venturi nozzle may be introducedinto the main passageway of any conventional type of carburetor withfacility, by merely disconnecting the main passageway from the manifoldand by removing the throttle valve 39f This construction not onlyenables us to apply our invention to carburetors already in use inautomobiles, but enables us to readily replace the nozzle should itbecome damaged in use.

Now we desire it understood that although lbs we have illustrated anddescribed in detail the preferred forms of our invention, the inventionis not to be thus limited, but only in so far as defined by the scopeand spirit of 5 the appended claims.

We claim:

1. In carburetion apparatus a mixing chamber for air and fuel, a nozzledisposed in said chamber, means for spraying a jet of fuel into saidnozzle, an air passageway connected to said chamber and nozzle, a chokevalve disposed in said passageway, an insulated electrical contactmember connected to said choke valve and movable therewith,

an electrical conductor connected to said contact member, a resilientlymounted contact carried by said contact member, an external fixedcontact connected to said nozzle cooperable with said resilient contact,said conductor comprising a part of a grounded electrical circuit, agrounded connection secured to said nozzle and means for operating saidchoke valve to move said resilient contact into and out of cooperationwith said fixed contact.

2. In carburetion apparatus, a mixing chamber, a nozzle in said chamber,means for spraying a jet of fuel into said nozzle, an air passagewayconnected to said chamber and nozzle, a choke valve in said passageway40 for controlling the flow of air therethrough, a contact memberconnected to and insulated from said choke valve, an electrical circuitconnected to said member, a resilient contact carried by said member andan external fixed contact connected to said nozzle and cooperable withsaid resilient contact, said contact member being movable into and outof cooperation with said fixed contact by movement of said choke valve.

3. In carburetion apparatus, a mixing chamber, a nozzle in said chamber,means for spraying a jet of fuel into said nozzle, an air passagewayconnected to said chamber and nozzle, a choke valve in said passagewayfor controlling the flow of air therethrough, a contact member connectedto and insulated from said choke valve, an electrical circuit connectedto said member, a resilient contact carried by said member and anexternal fixed Contact connected to said nozzle and cooperable with saidresilient contact, said contact member being movable into and out ofcooperation with said fixed contact by move ment of said choke Valve,said nozzle comprising a conductor of relatively high resistanceconnected at one end to said fixed contact and having its other endgrounded.

In testimony whereof, we have hereunto subscribed our names.

ROBERT HAMILTON.

HERMAN V. CROON.

